Purely anecdotal, since I didn't do any testing before and after, but it seems to me that I'm charging both iPad and iPhone less since iOS5. I don't THINK I'm using them any less, and I'm none too careful about closing apps that use location services. I've been using the Mophie case with battery for a while now, and I'd recommend it. It will recharge the iPhone from a few percent to fully charged before it needs to be plugged in. Only downside is that it replaces the Apple 30 pin connector with a miniUSB so you need a different cable for charging. Also there is not, so far as I'm aware, a version for iPad.